Stabilizing device and method



l Fly wheel H. H. Dow A 1,731,236

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(5u Plan2) Filed Oct. 26, 1927 C) Q C) C) cpcralor I cir-wen bq lnqmc Fly wbn-l ATTO Eys.

j INVENToR.

Patented oa. 1s, 192e UNITED sTATEsj HERBERT mrow; or MIDLAND, MICHIGAN, AssIeNoE To THE Dow CHEMICAL co'M- PATENT oFFicE PANN, oIr'iiIIDLAND,- MICHIGAN, A CORPORATION 0E MICHIGAN l i sTAIaILIzINery DEVICE AND METIIoD Application' iea'otober 26, 1927. 4serial No. 228,852.-

The present improvements have more par ticular regard to a method and apparatus for` acter in handmay be employed upon aircraft, and particularly upon buoyant craft, ]ust as advantageously as upon watercraft.

To the accomplishment ofthe foregoing and related ends, the invention, then, consists of the steps and means hereinafter' fully described and particularly pointed out 1n the claims, the annexed drawings and the following` description setting forth 1n detail cerf tain means and one mode of carrying out the invention,-such' disclosed means and mode illustrating, however, but one of variousways in which the principle of the invention may be used. l;

In said annexed drawings Fig. 1 is a more or lessdiagrammatic repre-v sentation of an apparatus or mechanism adapted to carry out the present improved lmethod of stabilizing ships or like floating.

vessels; and Fig. 2 is a similar diagrammatic representation of one/form of' automatic control device suitable for usein connection with such apparatus. f f

As is we ll known, in rough lwater a ship rolls to port, then to starboard, back to port -and so on indefinitely, with a pendulum-like y motion. The forces tending to produce this' i rolling movement may not be very great relative to the weight of the ship, but the application is rythmic' and the pendulum-like swing or roll of the boat is built up gradually to large proportions by the persistent or successive applicationl of these relatively small forces. The present invention is designed to utilize forces developed by the ships engine or motor to resist or neutralize the forces that thu-s tend to produce the roll of a ship. Briefly stated, I may utilize either changes in propeller torque (where the ship or vessel 1s onedriven by a propeller) or changes in the f stored energy (momentum) of, a rotor suitably mounted on the ship or vessel, or I may combine the effect of changes in both such propeller torque and rotor momentum. l

l'Referring first to the useof the screw propeller in achieving the object of the invention,

it will be noted that incidentally to producing,

by means of a screw propeller, the axial thrust which'propels the boat through the water or other medium 'in which it is floating, a turn-- ing moment. To increase the rate of revoluis, the engine which is ixedly-mounted in the lship transmits to the propeller (or propellers where more than one is employed) its turning moment. To increase the rate of revolution of the propeller, increased turning momentor torquev is required and this turning y moment may therefore bevaried by Vvarying the rate of revolution of the prppeller.v The effect of this turning moment is' to cause the ship to rollslightly in? a direction opposite Y pellers will be neutralized one by the other so long as such moments are equal. If, however, the relative speeds of the two propellers be varied, the difference between the altered m0- ments of the port land starboard propellers may be made to act at will-toward port or starboard and tend to list the ship accord-V ingly.

Based on the foregoing., I have discovered vthat by varying the moment of torque delivsol ' ered by the ship to the water through the provpeller or propellers in such a way as to augmentthat torque when it is resisting the forces tending to roll the ship and for decreasing that torque when it is assisting the forces tending to roll the ship, the rolling may be measurably reduced. With a plurality of propellers having opposing torques, the stated result is accomphshed by increasing the speed and the consequent torque on one-propeller and at the same time decreasing the speed and consequent torque of the propeller rotatlng 1n the opposite direction-as required to resist the moment of the force tending to roll the ship. y

In addition to the moment of torque which is passed from the ship to the water through such a screw propeller, the stored energy of rotating parts, such as the propeller bladesA and connected motor is itself a factor as may be best illustrated by assuming an independent rotating member to be mounted in the ship with its axis of rotation parallel to that of the ship. In such case the momentum of the rotating member is something external vtothe ship and if its rate ot rotation be'A changed, a commensurate force 'must be transmitted .to it through its mounting on the ship resulting in alike reaction upon its mounting but 1n an opposite directlon producing a moment of torque tending to roll the assembly of rotor, mounting and ship about the rotor axis in a direction opposite to the direction tions by corresponding electric motors it, the

latter being so connected electrically that generated voltages are opposite and that when rotating at the same speed, no current will pass between them or, in other words, no power will be delivered by one` to the other. Under such conditions, the electric motor drives will merely overc'omewindage and friction. For convenience in drawing layout, the rotors are shown as spaced laterally,

.but it'will be' understood that in practice they will be' located to secure most direct effect. The electric current connections be- Atween the machines are so arranged that the voltage control will be actuated by a. suitable stabilizing means, for instance a control gyroscope or pendulum, etc., in such a way that listingpf the ship will lower the voltage on one of the machines or both lower the voltages on the one and raise it onthe other, thus causing a power current to flow from one machine tothe other insuch a way that one will act as a generator and the .other as av motor driven by its companion. The generating force will be .the low torque delivered bythe driving motor plus the heavy torque delivered by the heavy generator rotor due to sudden retardation under the load. The companion rotor willbe accelerated due lto the power input received from the generator and the turning moment delivered to the ship through the stationary parts of the motor generators by retardation and vacceleration of the rotors will resist the turning moment of the outside forces tending to. list the ship in onedirection.

By reversing the above sequence of events, that is, by using the first rotor as motor'ald the second as generator, the effect of theturning moment delivered by the acceleration and retardation respectively of the two rotors 'will be ,opposite to' that just described and will resist turning moment of outside forces tending -to list lthe ship in that directlon In other words, the two motor generators w1ll alternately deliver and receive power from i each other inv sequence determined by the pendulum, -gyroscopic or other devlce which may be used to .actuate the voltagecontrol mechanism. The total energy which has been stored up in the rotors by the driving motors will remain a substantially constant amount equally divided betweenthem (if alike)l when'running at the same. speed, but unequally divided when at different speeds. The voltage cont-rol actuated by the stabilizing device will then cause shifting of energy from rotor to rotor back and forth in such a way that the torque developed by such shifting will resist the tendency of the boat to list by reason of outside forces.

The manner in which the torque of the propeller may be combined with the momentum of the rotor to act in a stabilizing manner is likewise shown in the drawing, which illustrates the use of a single propeller, it being suiicient to'explain that the same stable device that controls the electric current lconnections between motors 4 is also connected either directly or preferably through suitable relay mechanism with the speed control mechanism of the engine 2 or equivalent turbine or motor that drives the propeller. The connection between such deviceand speed ycontrol mechanism of the power unit is so ar- Jranged that when the pendulum swings to starboard, it will vary the propeller speed to increase the moment 'of torque to port or reduce it to port, depending upon the direction of `rotation of the propeller, and vice versa, when the pendulum swings toport, it I will act to var the speed so as to increase the moment o torque to starboard or decrease its moment to port.

For convenience in illustration a pendulum control is shown, but it is to be understood that any suitable control may be used,

a gyroscope4 being especially desirable. As illustrated, a pendulum 5 is mounted to swing on a pivot 11, 'such pendulum being hung so as to swing transversely of the ship and its pivot being preferably located at the center of oscillation. Dampening means (not shown), inthe form of dash pots, for example, will be provided to pre-vent undue oscillation of the pendulum. Attached to the latter is a segmental gear 12 .that engages with a pinion 13 with'which is connected a centrifugal contactor 14. When in operative position the latter closes the circuit through leads 15 and 16, the first of which is connected with a contact 17 mounted on theupper end l of the pendulum adjacent the pivot 1'1,`while the other is connected at an intermediate point with a solenoid 18. The respective ends of said solenoid are `suitably connected. with adjustable contacts 19 and20located o'n opposite sides of the contacts-17 and carried upon a'loose collar 22 journaled freely on the pivot 11. Armature 21 of the solenoid is connected byl means of a; rod to the previously described device whereby the changes in speed -of the engines, turbines or other I rotating membersv in the ship, which changes are to be utiliz ed for stabilizatlon, are accomplished.

The operatlon of the device inst described may now be briefly set forth. Assuming the' ship to be on even keel, the pendulum willJ be at rest with all contacts openand the rotating members running at equalsp'eedl If now 4the ship begins to list to port, the pendulum starts to swing to port, makinga starboardl contact and the centrifugal contactor'revolves an closes the circuit to energize the starboard end of the solenoid. The armature of the latter consequently is shifted t0 starboard and operates speed control mechanism to accelerate the starboard rotor and/or screw and to retard the. port rotor and/or screw'. When the in;

crease in list to port stops, the pendulum swing ceases, the centrifugal contactor ceases to .revolve and opens the circuit through the solenoid, the-.armature of which returns to neutral. As a result the speed control mecha'.-

nism is caused to retard. the starboard rotor and screw and accelerate the port rotor and screw towards equal speeds and initial status. When the ship begins to right itself, the -sglenoid will be reversel actuated to develop acceleratingand retar ing forces oppositeto those just described.

When neither` end of the solenoid is ener-v gized, the armature 21 isl automatically returned to neutralposition in which position it has moved the speed changing device to restore the rates of rotation of the rotor,

rotorsor propellerv to normal vand when either the port erstarboard end of the solenoid is energized, the armature will move to port or starboard, and in such positions will operate to change the rates of 'rotation ofthe propeller or the rotor or rotors todevelopa 'V reaction opposed to the direction in which the ship isrolling. .l

It will thus be seen that I provide in general a stabilization by positive and negative acceleration of rotating parts as determined by requirements; and where commensurate alternate acceleration and retardation is applied to paired rotors electrically coupled and lturning in opposite directions', the simulta- -neous reaction on, .the ships hull may be doubled in eitherdlrection and may persist in accordance with anyfcrafts natural-half period. Moreover, the system is applicable in various arrangements, Ycompensatively changing the speed of the turbines or other -prime movers changing the propeller torque,

nationally, as desired.

Other modes of applying .the Aprinciple vof my invention may be employed instead of the .one explained, change being -made as regards the means and the steps herein disclosed', pro- -opposing moment by varying thef speed of the propeller in such manner as to increase said moment when it will resist the forces tending to roll the ship and to decrease said moment when itwill resist such. forces.

2. A method of reducing the roll of a ship, which comprises varyin the speed of the propeller of the ship as t e latter rolls'so as tol vary the torque reaction of such propeller, and simultaneously varying the speed of a rotating member' properly mounted inthe ship so as to oppose the reaction due tothe acceleration or eceleration of said member to the rolling action of the ship. l

3. A method ofreducing the roll of aship,

Vwhich comprises automatically varying thespeed of the'propeller of the ship as the latter lrolls so asto oppose' the change'in the torque reaction of such propeller to the rolling actlon of the ship, and simultaneously automatically varying t e speed of a rotating member propvor changing the inertia of a rotor, or combierly mounted in the ship so as to oppose the reaction due to. the acceleration or deceleration of said member to the rolling laction of the ship.

4. In a ship stabilizer, the combination with two rotating members mounted in the ship, means .interconnecting said members whereby deceleration of either one'will'accelerate the other, the operation of said means, being controlled by the rolling of the ship,

and means for simultaneously varying the.

- vpropeller speed.

5. Means for stabilizing propeller driven i craft, tworotating members mounted on the craft, means 1nterconnect1ng sald 'members whereby deceleration of either-one will accelerate the other, land means includingin coml bination with the propeller,l means adapted Aautomatically to very the speed of said ropeller as the ship rolls and vary the Spee of the rotating members correspondingly.

Signed by me, this 20th day of October,

HERBERT H. DOW. 

